Consecutive thermomagnetic beneficiation of Turkish lignites

The results of investigations of beneficiation regularities of Tavsanlt-Ome rler lignites in a two-stage consecutive process of heat treatment and magn etic separation are presented. After thermal treatment of lignite samples i n a rotary kiln at temperatures ranging from 370 to 650 degreesC, the appli cation of the REMS magnetic separator produces a product higher in calorifi c value (6727 kcal/kg) and lower in sulphur (1.27 %) and ash (8.5%) content . The mechanisms of the process have been investigated by scanning electron microscopy, chromatography, electron spin resonance, X-ray diffractometry, derivatography and chemical analysis. The efficiency of the beneficiation processes can be explained by the impro vement of magnetic properties of pyrite during heat treatment due to oxidat ion (T < 400<degrees>C) and decomposition (T > 400 degreesC) of pyrite and compact distribution of part of organic sulphur around pyrite grains. (C) 2 001 Published by Elsevier Science Ltd.